A tyre changing apparatus (1) comprises: a frame (10); a supporting element (11) for supporting a wheel (2) rotatably about an axis of rotation (A); an arm (12) movably connected to the frame (10) to be moved by an actuator (5B, 5B′) along a direction of movement (B) parallel to the axis of rotation (A); a bead breaker tool (13) connected to the arm (12) to move between an activated position, where it is in contact with the tyre (3), and a deactivated position, where it is spaced from the tyre (3); a control unit (14). The bead breaker tool (13) includes a mounting element (13A) and a bead breaker disc (13B) which rotates freely relative to the mounting element (13A) and comprises a sensor (131), configured to generate a contact signal (132) representing a rotation of the bead breaker disc (138) relative to the mounting element (13A); the control unit (14) is connected to the sensor (131) to receive the contact signal (132).